Meta-analysis of phenotypic plasticity in response to thermal treatments in invertebrates

Populations must adapt to environmental changes to remain viable. Both
evolution and phenotypic plasticity contribute to adaptation, with
plasticity possibly being more important for coping with rapid change.
Adaptation is complex in species with separate sexes, as the sexes can
differ in the strength or direction of natural selection, the genetic
basis of trait variation, and phenotypic plasticity. Many species show sex
differences in plasticity, yet how these differences influence extinction
susceptibility remains unclear. We first extend theoretical models of
population persistence in changing environments and show that persistence
is affected by sexual dimorphism for phenotypic plasticity, trait genetic
architecture, and sex-specific selection. Our models predict that
female-biased adaptive plasticity—particularly in traits with
modest-to-low cross-sex genetic correlations— typically promotes
persistence, though we also identify conditions where sexually monomorphic
or male-biased plasticity promotes persistence. We then perform a
meta-analysis of sex-specific plasticity under manipulated thermal
conditions. Although examples of sexually dimorphic plasticity are widely
observed, systematic sex differences are rare. An exception—cold
resistance—is systematically female-biased and represents a trait wherein
sexually dimorphic plasticity might elevate population viability in
changing environments. We discuss our results in light of debates about
the roles of evolution and plasticity in extinction susceptibility.